As most of you know I have been keeping aloes for a long time with very few losses . This fall I have ran into a rot problem that seems to be systematically taking down my plants . Yesterday I caught one before it was total mush so I could take some pics before it dies
I am leaning towards root rot but I have seen the occasional black shiney round marks on my plants . This seems to clear with fungal treatment. These marks are tiny and nothing that looks like a major issue . I have been resisting a mass fungicide spray because I know these chemicals are not exactly harmless to the plants they just kill the fungus and bacteria faster
I am at the point now where I feel I need to do something drastic . We have have the wettest summer in a long time here so a lot of humidity
I have not watered the plants for weeks the soil in the pics is dry and does not stick to your hand

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I have made sure there is air movement. The latest plant to go was literally closest to the fan . You can feel the air pushing on you on that location
I have been keeping the plants at 10 degrees c overnight with heating
I have stopped watering early this year
I have changed a lot of topping gravel for a more porous moler clay
What to do next ?
I could treat all pot with a peroxide to kill any root level negative bacteria . Risk is I will cause rot again on plants because of the time of year
I could spray all plants with fungal treatment?
I could spray all plant surfaces with alcohol
I could of course do more than one
Anyone have any views ?

I would think there is enough bright light in your greenhouse, looking at the red color?
Thinking warm sunshine. Perhaps adding additional clamp-lights on a timer above them?

https://garden.org/thread/view...

I still can see healthy roots in there, then I will assume that rot is not from the roots, but from the base of the leaves.
How long do you have this aloes that rotted? More than 2 years? I think you just install the polytunnel less than 1 year. What are the major differences in the summer months that the plants experiencing between this and last year?

I can't really offer much here, given the huge differences in how our aloes grow (the greenhouse, the months without water) ... just some thoughts about treatment. Peroxide is toxic to plants at a sufficiently high dose, so if you go that route (as with any chemical treatment) be sure to measure and use the product in moderation. Alcohol (I use 70%) is tolerated very well by aloes above ground, but I doubt that is the case for the roots. At some point once you spray enough on the leaves, you will begin to treat the roots. So again apply in moderation, to avoid adverse consequences. Not sure either treatment will do much good, but at least you can avoid them doing actual harm.

When one of my plants loses its roots to rot, I tend to shrug and toss it without investigating further. So I really have very little idea what kind of organism is involved, often I am clueless about what the inciting event might be. Except that it tends to be associated with (1) too much water (at one time or over time), (2) roots being weak to start with, and/or (3) the pot having too much soil for the size the roots (probably through mechanism #1 above).

Also worth noting that root loss to rot may also be related to insufficient water over the long term. This perverse mechanism seems to be related to some kind of chronic weakening of the roots (see mechanism 2 above) which leads to a rapid collapse when they are finally watered properly. So it's not so much the watering but the insufficient watering preceding it that makes things go south. Probably not the issue for you Steve, just including it here for the sake of completion. Especially not relevant in the face of this upcoming drought which you apply during winter, which is very different from withholding water during active growth, and which has worked very well for you in the past.

Weird to be typing without my left index finger, so I will stop soon. I lopped off the tip of my finger yesterday with scissors as I was trying to take a Dudleya cutting. The Dudleya cutting will likely survive but the human cutting was lost somewhere inside the mother plant. Much blood, so much blood, the dog was very interested in my bloody bandage in the aftermath.

That is a big ouchy! That hurts just thinking about it. Hope you heal fast!

Ouch! Another example of the hazards of growing live plants. Lot more weaponry involved than folks realize.

@Ursula
@Kaktus
@Baja_Costero
@needrain
Thanks all for responses . Clearly Some parameters are at the limits of acceptability but it's surprisingly difficult to pin down the cause . I don't think it is air fungus as there are no significant build ups on the leaf surfaces . More likely that I have gone too far on the upotting or adding in fertiliser , or the switch to bamboo pots is trapping excessive moisture. I think it's too late now to start uprooting everything so I guess it's a case of just trying to ride it out now until next spring
Steve

@Baja_Costero
Luckily we are not like plants and you won't frow 4 branching fingers from where you made the cut . Sounds very painful I hope it heals ok
Steve

ketsui73 said: @Baja_Costero
Luckily we are not like plants and you won't frow 4 branching fingers from where you made the cut . Sounds very painful I hope it heals ok
Steve

I dunno, Steve. There have been plenty of times when I could have used an extra hand!

I didn't grow extra hands, but for sure my hair turn into silver variegation

Ouch Baja so sorry to hear that! I can't unsee in my head what you lost!

Steve, I think the combination of uppotting with more than the needed fertilizer could be the culprit. This happened on some of my desert rose seedlings and they literally got amputated. If there are no black rot, then it is likely not a fungus. The good thing about aloes per my experience (which is limited) is even when I accidentally pull them without roots; I just put them an inch on top of a media and they develop roots.

Steve, I am hoping this situation improves for you, and would appreciate updates if you take action or learn something useful.

By way of unrelated update from my side, here is my recovering fingertip and the associated Dudleya cuttings. All is ending well here, I think.

@Baja_Costero
Thanks for the update and encouragement. Pleased to see you and the plant are recovering well.
Despite threatening to 'go nuclear' earlier in this thread I have not done anything drastic . I have treated some plants (with signs of leave movement) to a watering with peroxide to try to stem any rot that may be starting at the root level . Nervous times now while I wait for them plants to dry out . So I am now in a cycle of nervous early morning and evening plant inspections pushing on leaves to try to detect early signs of rot
We have just had the warmest sept on record and oct has started in a similar vein . Unfortunately higher temps are not translating to more dry sunshine , but endless wet and windy weather . Summer was a total washout and the rain just keeps falling .I think it's a combination of high humidity, low light and bigger pots that has pushed my luck too much
I will update the thread if anything else comes to light
Steve